Active matrix drive fluorescent display device and method for manufacturing same

Abstract

An active matrix drive fluorescent display device capable of preventing misluminescence of phosphor layers. A semiconductor chip which includes a plurality of luminous dots arranged in a matrix-like manner and is arranged in an envelope is covered on a cut surface thereof rendered electrically GND with an insulating cover layer. Such construction eliminates a failure in insulation between electrodes arranged on the semiconductor chip, to thereby prevent misluminescence of the luminous dots, leading to an increase in display quality.

What is claimed is:  
     
       1. An active matrix drive fluorescent display device comprising: 
       an envelope;  
       a semiconductor chip arranged on an inner surface of said envelope;  
       a plurality of anodes arranged in a matrix on said semiconductor chip and individually driven;  
       said anodes each having a phosphor layer deposited thereon; and  
       filamentary cathodes arranged in said envelope so as to be positioned above said semiconductor chip,  
       wherein said semiconductor chip is covered on an end surface thereof with an insulating material,  
       and said insulating material comprises a fine powder of a material selected from a group consisting of Al 2 O 3 , SiO 2 , ZrO 2  and frit glass.  
     
     
       2. An active matrix drive fluorescent display device comprising: 
       an envelope including a substrate;  
       a semiconductor chip arranged on an inner surface of said substrate of said envelope;  
       switching elements arranged in a matrix on said semiconductor chip and selectively driven;  
       anodes arranged on respective of said switching elements and having a phosphor layer deposited thereon;  
       a control electrode arranged on said semiconductor chip in a manner to extend between said anodes adjacent to each other; and  
       filamentary cathodes each including an electron emitting layer made of a metal oxide and arranged in said envelope so as to be positioned above said semiconductor chip,  
       wherein said semiconductor chip is covered on a first cut surface thereof with an insulating material,  
       and said semiconductor chip includes an electronic element other than said anodes and switching elements formed at a portion of the semiconductor chip in proximity to an outer edge of an upper surface of said semiconductor chip, and  
       said insulating material covers a second cut surface of said semiconductor chip not in proximity to said electronic element.  
     
     
       3. A method for manufacturing an active matrix drive fluorescent display device including an envelope including a substrate, a semiconductor chip arranged on an inner surface of said substrate of said envelope, anodes arranged in a matrix-like manner on an upper surface of said semiconductor chip and selectively driven, said anodes each having a phosphor layer deposited thereon, and filamentary cathodes arranged in said envelope so as to be positioned above said semiconductor chip, comprising the steps of: 
       coating a liquid on a cut surface of said semiconductor chip fixed on said substrate of said envelope, said liquid being prepared by dispersing a fine powder of an insulating material in a solvent; and  
       calcining said substrate to cover said cut surface of said semiconductor chip with said insulating material.